For some specific applications, it is desirable to operate arc lamps, having a short arc space, in series because the voltage drop of such lamps is relatively low, (15-18 volts), and individual lamp operation (that is, with the lamps connected in parallel) results in inefficient high current power transfer from the associated power processing circuitry. By operating arc lamps in series, a higher effective voltage is presented to the power conditioning circuitry, and improved system power transfer efficiency is thereby achieved. Improved efficiency is especially important because the arc lamps may be modulated at peak currents as high as 400 amps and with duty cycles in excess of 50%.
On the other hand, ignition of series connected arc lamps usually requires a voltage on the order of: the voltage required to ignite an individual arc lamp, multiplied by the number of arc lamps in the series. The ignition voltage for typical arc lamps is on the order of 11,000 volts. Thus, a string of arc lamps could require 22,000 volts, 33,000 volts, and upwards, depending on how many lamps are in the series string. One use for multiple arc lamp sets is in jamming infrared tracking systems on aircraft. In high altitude airborne environments, the voltage standoff spacing required for this level of ignition voltage (in excess of 22,000 volts) is prohibitive.